Merge pull request #74 from janestreet/v0.12.0-for-win

backport fix for popcount detection on windows

src/discover/discover.ml

@@ -0,0 +1,20 @@
+open Configurator.V1
+
+let program =
+  {|
+int main(int argc, char ** argv)
+{
+  return __builtin_popcount(argc);
+}
+|}
+;;
+
+let () =
+  let output = ref "" in
+  main
+    ~name:"discover"
+    ~args:[ "-o", Set_string output, "FILENAME output file" ]
+    (fun c ->
+       let has_popcnt = c_test c ~c_flags:[ "-mpopcnt" ] program in
+       Flags.write_sexp !output (if has_popcnt then [ "-mpopcnt" ] else []))
+;;

src/discover/discover.mli

@@ -0,0 +1 @@
+(* empty *)

src/discover/dune

@@ -0,0 +1,2 @@
+(executables (names discover) (libraries dune.configurator)
+ (preprocess no_preprocessing))

src/dune

@@ -24,13 +24,7 @@
    -apply=js_style,base_lint,type_conv))
  (js_of_ocaml (javascript_files runtime.js)))
 
-(rule (targets mpopcnt.sexp) (deps)
- (action
-  (progn
-   (with-stdout-to popcnt_test.c
-    (echo
-     "int main(int argc, char ** argv) { return __builtin_popcount(argc); }"))
-   (system
-    "%{cc} -mpopcnt -c popcnt_test.c 2> ${null} && echo '(-mpopcnt)' > %{targets} || echo '()' > %{targets}"))))
+(rule (targets mpopcnt.sexp) (deps discover/discover.exe)
+ (action (run ./discover/discover.exe -o %{targets})))
 
 (ocamllex hex_lexer)

test/test_map.ml

@@ -44,7 +44,6 @@ let%expect_test "[Map.of_alist_multi] preserves value ordering" =
      (b (1 3))) |}]
 ;;
 
-
 module Poly = struct
   let%test _ =
     length Poly.empty = 0
@@ -61,4 +60,3 @@ module Poly = struct
     length a = length b
   ;;
 end
-